Serum separation apparatus and method

ABSTRACT

1,066,165. Semi-conductor devices. DEUTSCHE AKADEMIE DER WISSENSCHAFTEN ZU BERLIN. Aug. 6, 1965, No. 33753/65. Heading H1K. A metal layer is formed on a P-type semiconductor body and lithium is deposited on the layer, the body then being heated to simultaneously temper the metal layer and diffuse lithium into the body to form an N-region and ohmic contact thereon. Suitable semi-conductors are silicon, germanium, and gallium arsenide. Suitable metals are nickel, silver, gold, and aluminium. In an embodiment a 400 ohm. cm. P-type silicon wafer is cleaned ultrasonically in trichloroethylene, etched in hydrofluoric acid, and boiled several times in deionised water before it is nickeled in a hot chemical bath. The nickel is coated with lithium by vapour deposition and the body heated to 600‹ C. After slow cooling the main faces of the wafer are masked and nickel is etched from the edges. The process is completed by a wash in trichloroethylene.

Nov. 28, 1967 A. F. FARR SERUM SEPARATION APPARATUS AND METHOD FiledJuly 6, 1964 FIG. 5

FIG. 4.

INVENTOR 41701751! IT H I ATTORNEY United States Patent 3,355,098 SERUMSEPARATION APPARATUS AND METHOD Andrew F. Farr, South Gate, Califl,assignor to Bioconsultants, Inc., Glendale, Califi, a corporation ofCaiifornia Filed July 6, 1964, Ser. No. 380,497 8 Claims. (Cl. 233-26)This invention relates to the method and apparatus for separation ofserum from dispersed solids, particularly blood serum from suspendedcells, for the purpose of obtaining samples of clear serum.

One object of the invention is to provide a method for easy separationof a liquid from suspended solids. Another object is to provide meansfor easily and quickly separating blood serum from the cellular bodieswhich have been settled to the bottom portion of a tube, for example asby centrifuging. A further object is to provide inexpensive anddisposable apparatus for the removal and storage of the serum from acentrifuged tube of blood. Another object is to provide means foraccurately separating one immiscible liquid from another, in a tubularcontainer.

These and other objects are attained by my invention which will beunderstood from the following description, reference being made to theaccompanying drawings in which-- FIG. 1 is a side elevational view of anassembled serum separation apparatus;

FIG. 2 is a cross-sectional view taken on the line 2-2 of FIG. 1;

FIG. 3 is a side elevational view of the same in disassembly with partsbroken away and shown in section;

FIG. 4 is a diagrammatic representation of the apparatus in use showingthe delivery of serum to the upper chamber of the apparatus fortemporary storage therein;

FIG. 5 is a diagrammatic representation of the apparatus in use showingdelivery of serum to another vessel; and

FIG. 6 is a side elevational view of an alternative arrangement with ashortened capillary tube discharging within the plunger tube.

In the examination of blood samples in a clinical laboratory, it isfrequently necessary to examine the blood serum after separation fromthe suspended cellular material, and for this purpose it is customary tosubject the tubes in which the blood samples are delivered to thelaboratory, to centrifugal force to cause the settling of the cells tothe bottom of the tube. In certain clinical laboratories, hundreds oftube samples of blood are handled per day, and it is important toconserve time and provide completely accurate identification (byattached labels) of each sample both before and after separation of theserum from the solids.

In FIG. 1 there is shown an assembled separation apparatus consisting ofan outer tubular member 11, which is generally a sample tube in whichthe blood sample has been delivered to the laboratory, and in which theblood may be subjected to centrifuging to settle out the cells. Aplunger tube 12 having a soft rubber piston head 13 attached to itsinner end is arranged to be moved longitudinally within and slidinglyfitting the inside wall of the member 11, the plunger tube 12 beingconsiderably longer than the tube 11 to provide handle means. The outerend 14 of the plunger tube 12 is open, and there is provided within saidtube a plastic flexible small bore or capillary tube 15, whose lower end16 extends through an opening 17 provided in the piston head 13, andwhose opposite outer end 18 may extend beyond the open end 14 of'theplunger tube 12, although it may terminate within the 3,355,098 PatentedNov. 28, 1967 plunger tube if desired. The outer end portion 18 of theflexible tube 15 may be doubled back into the plunger tube 12 (as shownin FIG. 4) or it may be free to communicate with another receivingvessel 19.

The method of separating the serum from the suspended solids starts withthe centrifuging of the blood sample in the tube 11, following the wellknown test procedure. After centrifuging, the plunger tube 12 withpiston head 13 is inserted in tube 11, the capillary tube 15 being inplace with its lower end attached to and penetrating the piston head 13so that its lower end communicates with the gas or liquid contents ofthe tube 11 below the piston head 13. As the head 13 is pressed into thetube 11, the air above the serum 20 is released to the atmosphere, andwhen the end of the capillary tube which extends through the piston head13 makes contact with the serum 20, the serum passes out through thecapillary tube 15, without disturbing the settled out solids or cellularbodies 21. If the outer end 18 of the capillary tube is doubled back toreenter the plunger tube 12, as shown in FIG. 4, the separated serum iscollected and retained above the piston head 13 in the plunger tube 12,where it may be kept until required for further examination.Alternatively, as shown in FIG. 5, the outer end 18 of the capillarytube 15 may be extended outside the plunger tube 12, to deliver serum toany desired receiving vessel 19. A portion of serum may be placed in thereceiving vessel 19, or several such vessels, and then the remainder ofthe separated serum may be collected and retained in the plunger tube12, by doubling back the outer end 18 of the capillary tube 15 into theplunger tube. The piston head 13 may be pressed down until all of theseparated serum 20 above the settled out solids 21 has been-removed. Theportion of the serum which surrounds the cells or solid particles is notremoved. Because of the extension of the capillary tube 15 outside theplunger tube 12, the serum in said plunger tube 12 may not return to thetube 11.

In an alternative arrangement, the capillary tube 15A may terminateinside the plunger tube 12 as shown in FIG. 6, in which arrangement theseparated serum is collected in the plunger tube 12, from which it maybe removed by pouring or in any other convenient manner.

After the separation has been completed, and the retained separatedserum is no longer needed, the plunger tube 12, with piston head 13 andcapillary tube 15 may be removed and discarded. The tube 11 is generallycleansed and re-used for new blood samples, but if desired, the entireapparatus may be discarded, since the apparatus is very inexpensive,whether made of glass or of synthetic plastic, thus avoiding washing andre-sterilizing.

While the use of the apparatus has been described with reference to theseparation and collection of blood serum, the apparatus has other uses.For example, it may be advantageously used to remove a separated toplayer in a tube containing immiscible liquids, as sometimes used inliquid extractions, particularly for analytical purposes. It may also beused for removing relatively large amounts of liquid from a settledsmall body of an analytical precipitate in a tube, in completing wellknown analytical procedures.

Where the descriptive Word capillary is used herein it refers tosmall-bore plastic tubing having a bore of about inch.

The advantages of the method and use of the apparatus will be apparentfrom the above description. The saving in handling time for making theseparation, and the avoid ance of re-labeling of the temporarily storedserum (avoiding the danger of mislabeling) make the invention useful inanalytical examinations.

The objectives stated in the beginning have been attained.

I claim:

1. An apparatus for separating a clear liquid from settled-outimmiscible liquids and/ or settled-out solids in a suspending liquidcontained therein, comprising an outer transparent tubular member; aplunger tube longitudinally movable within said outer member; a pistonhead mounted on the closed inner end of said plunger tube, said pistonhead making sliding sealing contact with the inner walls of said outertubular member, and flexible capillary tube disposed within said plungertube, one end of said capillary tube extending through said piston headto communicate with the space in said outer tubular member below saidpiston head.

2. An apparatus for separating a clear liquid from settled-outimmiscible liquids and/or settled-out solids in a suspending liquidcontained therein, comprising an outer transparent tubular member; aplunger tube longitudinally movable within said outer member; a pistonhead mounted on the closed inner end of said plunger tube, said pistonhead making sliding sealing contact with the inner walls of said outertubular member, and flexible capillary tube disposed within said plungertube, one end of said capillary tube extending through said piston headto communicate with the space in said outer tubular member below saidpiston head, said flexible capillary tube extending out of the oppositeopen end of said plunger tube.

3. The apparatus defined in claim 2 in which the outer end of thecapillary tube is doubled back so that it communicates with said plungertube.

4. In an apparatus for separating a clear liquid from separated outsolids, contained in a centrifuge tube, a plunger tube longitudinallymovable within said centrifuge tube; a piston head mounted on the innerend of said plunger tube, said piston head making sliding sealingcontact with the inner walls of said outer tubular member, and aflexible capillary tube disposed within said plunger tube, one end ofsaid capillary tube extending through said piston head to communicatewith the space in said tubular member below said piston head.

5. In the plunger tube defined in claim 4, a flexible capillary tubewhich extends beyond the outer end of said plunger tube.

6. In the plunger tube defined in claim 4, a flexible capillary tubewhich terminates inside said plunger tube.

5 7. The method of removing a separated lighter liquid from a heaviermaterial contained in the bottom portion of a first zone comprising:

(a) Applying mechanical pressure by pushing tubular plunger meansagainst the surface of the overlaying liquid whereby the end portionmeans of said plunger means decreases the volume of said bottom portionof said first zone;

(b) Relieving said pressure by displacing said lighter liquid fromsubstantially the surface portion thereof through orifice means in saidend portion of said plunger means;

(0) Moving said displaced liquid from said surface through conduit meansdisposed internally of said plunger means and distinct from the tubularwall of said plunger means to a point displaced from said surfacecontacted by said plunger means;

(d) Then flowing said moved liquid into a second zone.

8. The method of claim 7 wherein the second zone is within the bottomportion of said tubular plunger means.

References Cited UNITED STATES PATENTS 2,362,081 11/1944 Martin 103-1882,394,189 2/1964 Kaufman 103188 X 3,131,646 5/1964 Parrott 103--188 X1,591,604 7/1926 Bienenstok 222-320 1,714,482 5/1929 Schmuziger 222320FOREIGN PATENTS 1,888 1/1893 Great Britain.

OTHER REFERENCES German printed application 1,014,348, August 1957.

HENRY T. KLINKSIEK, Primary Examiner.

M. CARY NELSON, Examiner.

1. AN APPARATUS FOR SEPARATING A CLEAR LIQUID FROM SETTLED-OUTIMMISCIBLE LIQUIDS AND/OR SETTLED-OUT SOLIDS IN A SUSPENDING LIQUIDCONTAINED THEREIN, COMPRISING AN OUTER TRANSPARENT TUBULAR MEMBER; APLUNGER TUBE LONGITUDINALLY MOVABLE WITHIN SAID OUTER MEMBER; A PISTONHEAD MOUNTED ON THE CLOSED INNER END OF SAID PLUNGER TUBE, SAID PISTONHEAD MAKING SLIDING SEALING CONTACT WITH THE INNER WALLS OF SAID OUTERTUBULAR MEMBER, AND FLEXIBLE CAPILLARY TUBE DISPOSED WITHIN SAID PLUNGERTUBE, ONE END OF SAID CAPILLARY TUBE EXTENDING THROUGH SAID PISTON HEADTO COMMUNICATE WITH THE SPACE IN SAID OUTER TUBULAR MEMBER BELOW SAIDPISTON HEAD.